1. Field of the Invention
This invention relates to a method for correlating images and, more particularly, is preferable to such applications as differences or changes of an object image are detected with referring to a reference image to recognize or control the object.
2. Description of the Prior Art
An art to perform pattern matching is important in applications which need to identify an object, or to find out, to inspect, to position-control the object and so on. It is one of essential problems in the art of the pattern matching to accurately correct a positional shift and rotational shift of the object image to the reference image.
In the prior art, the center of gravity of an input image and the first-order moment are calculated to detect the positional and rotational shifts for correcting these shifts with referring to the reference image.
According to the prior art, accuracy of correcting the position and rotation is insufficient and is affected by noises mixed in an image signal.